CN103955014A - Manufacturing method of micro-lens arrays - Google Patents

Abstract

The invention relates to a manufacturing method of a microlens array, including: (1) designing and generating a required microlens array model, and setting corresponding laser power, laser beam spot size, and laser dwell time according to the parameters of the required microlens array; ( 2) Provide a clean substrate and make a micro-concave array on the substrate by laser dotting; (3) Coat the silicone rubber prepolymer evenly on the surface of the micro-concave array, and prepare a silicone rubber micro-lens array after curing and separation; (4) Transfer the silicone rubber microlens array to other materials to prepare microlens arrays of different materials; (5) Perform subsequent polishing on the microlens array. The method can be used to prepare high-precision and large-area microlens arrays, and the manufacturing cost is low.

Description

A method of manufacturing a microlens array

technical field

The invention relates to the technical field of micro-nano processing and manufacturing, in particular to a method for manufacturing a micro-lens array.

Background technique

Microlens array refers to an array formed by a series of microlenses with a diameter between several microns and several millimeters arranged in a certain way, which can realize the focusing, emission, deflection, division, recombination, switching, coupling, receiving, etc. of light beams. It is one of the important components of the micro-optical system and is widely used in naked-eye stereoscopic display, beam shaping, fiber coupling and other fields. At present, the manufacturing methods of the microlens array mainly include: (1) A metal mold is prepared by a mechanical method, and then the microlens array is prepared by an inverted mold method. The microlens array prepared by this method has high precision and can prepare a large-area microlens array, but the disadvantage is that for microlens arrays with different parameters, it needs to be molded again, and the mold opening is expensive and the cycle is long, which leads to the failure of this method. Microlens arrays are expensive. (2) Microlens arrays based on photoresist materials are prepared by using photoresist hot-melt technology. The process of this method is complicated, and the parameters of the prepared microlens arrays are difficult to control. On the other hand, laser processing has the advantages of high processing precision, flexibility, and speed. With the development of laser technology, laser processing has been widely used in dotting, marking, cutting and other fields. The light guide dots on the light board are more commonly used, and have many advantages such as large processing size, fast speed, and low cost.

In view of the shortcomings of the existing microlens array preparation methods and the advantages of laser processing technology, the present invention adopts laser processing to prepare micro-concave array molds, and uses soft printing transfer technology to prepare microlens arrays of different materials, and proposes a high-precision, large-scale Area, low-cost microlens array fabrication method.

Contents of the invention

The object of the present invention is to provide a method for manufacturing a microlens array in view of the disadvantages of traditional microlens array preparation methods, such as complex process and high manufacturing cost, and laser processing has many advantages such as large processing size, fast speed, and low cost.

To achieve the above object, the technical solution of the present invention is: a method for manufacturing a microlens array, comprising the following steps,

S1: Design and generate the required microlens array model, and set the corresponding laser power, laser beam spot size and laser dwell time according to the parameters of the required microlens array;

S2: Provide a clean substrate and make a dimple array on the substrate by laser dotting;

S3: Coating the silicone rubber prepolymer evenly on the surface of the micro-concave array, preparing a silicone rubber micro-convex lens array after curing and separating, and performing polishing treatment.

In the embodiment of the present invention, in the step S3, the silicone rubber micro-convex lens array is transferred to a substrate to prepare the micro-convex lens array of the substrate.

In the embodiment of the present invention, the silicone rubber micro-convex lens array is transferred to a substrate to prepare the micro-convex lens array of the substrate, and the specific process is as follows:

S41: Prepare a silicone rubber micro-concave array through the silicone rubber micro-convex lens array prepared in the step S3;

S42: Coating the substrate evenly on a flat substrate, placing the silicon rubber micro-concave array on the surface of the substrate, and preparing a micro-convex lens array of the substrate after curing and separation.

In the embodiment of the present invention, the material used for the substrate is a transparent organic polymer material that can be cured by ultraviolet or heat, including NOA81, UV glue, PMMA, PC, and PVP.

In the embodiment of the present invention, the material used for the substrate is organic polymer, metal, semiconductor, oxide or marble.

In the embodiment of the present invention, the lens distribution of the micro-convex lens array can be adjusted arbitrarily by design software as required.

In the embodiment of the present invention, the lens aperture and lens curvature radius of the microlens array are mainly determined by the laser beam spot size, laser power and laser dwell time, wherein the laser beam spot size is 1 micron to 5 mm, and the laser power is 1 Watts to 10 kilowatts with a laser dwell time of 5 microseconds to 5 minutes.

In the embodiment of the present invention, the wavelength of the laser used in the method is in the infrared band from 760 nm to 1 mm, and the frequency range is from 10 Hz to 10 MHz.

In the embodiment of the present invention, the subsequent polishing treatment in step S4 is mechanical polishing and chemical polishing treatment, so as to obtain a flat and smooth lens surface.

In an embodiment of the present invention, the lens size of the microlens array is 10 micrometers to 10 millimeters, and the size of the microlens array is 1 inch to 100 inches.

Compared with the prior art, the present invention has the following beneficial effects: Combining the characteristics of large processing size, high speed and low cost with laser processing technology, it provides a high-precision, large-area, and low-cost microlens array manufacturing method.

Description of drawings

FIG. 1 is a schematic flow chart of a manufacturing method of a microlens array in the present invention.

FIG. 2 is a schematic diagram of a microlens array designed in step (1) of the embodiment of the present invention.

3 is a schematic cross-sectional view of the PMMA micro-concave array produced by laser processing in step (2) of the embodiment of the present invention.

Fig. 4 is a schematic cross-sectional view of the silicone rubber PDMS microlens array prepared in step (3) of the embodiment of the present invention.

Fig. 5 is a schematic cross-sectional view of the silicone rubber PDMS micro-concave array prepared in step (4) of the embodiment of the present invention.

Fig. 6 is a schematic cross-sectional view of the NOA81 microlens array prepared in step (5) of the embodiment of the present invention.

In the accompanying drawings, the main components are marked as follows:

01—PMMA substrate; 02—microlens model; 03—PMMA microconcave array; 04—PDMS microlens array; 05—PDMS microconcave array; 06—NOA81 microlens array; 07—glass substrate.

Detailed ways

The technical solution of the present invention will be specifically described below in conjunction with the accompanying drawings.

A method for manufacturing a microlens array, comprising the following steps,

S1: Design and generate the required microlens array model, and set the corresponding laser power, laser beam spot size and laser dwell time according to the parameters of the required microlens array;

S2: Provide a clean substrate and make a dimple array on the substrate by laser dotting;

S3: Coating the silicone rubber prepolymer evenly on the surface of the micro-concave array, preparing a silicone rubber micro-convex lens array after curing and separating, and performing polishing treatment.

In the step S3, the silicone rubber micro-convex lens array is transferred to a substrate to prepare the micro-convex lens array of the substrate.

The described silicone rubber micro-convex lens array is transferred to a substrate to prepare the micro-convex lens array of the substrate. The specific process is:

S41: Prepare a silicone rubber micro-concave array through the silicone rubber micro-convex lens array prepared in the step S3;

S42: Evenly coat the substrate on a flat substrate, place the silicone rubber micro-concave array flatly on the surface of the substrate, and prepare the micro-convex lens array of the substrate after curing and separation; the substrate material can be cured by ultraviolet light Or heat-cured transparent organic polymer materials, including NOA81, UV glue, PMMA, PC, PVP.

The material used for the substrate is organic polymer, metal, semiconductor, oxide or marble.

The lens distribution of the microlens array can be adjusted arbitrarily by design software as required.

The lens aperture and lens curvature radius of the microlens array are mainly determined by the laser beam spot size, laser power and laser dwell time, wherein the laser beam spot size is 1 micron to 5 mm, the laser power is 1 watt to 10 kilowatts, and the laser stay The time is from 5 microseconds to 5 minutes.

The wavelength of the laser used in the method is in the infrared band from 760 nanometers to 1 millimeter, and the frequency range is from 10 Hz to 10 MHz.

The subsequent polishing treatment in step S4 is mechanical polishing and chemical polishing treatment, so as to obtain a flat and smooth lens surface.

The lens size of the microlens array is 10 microns to 10 millimeters, and the size of the microlens array is 1 inch to 100 inches.

In the drawings, the thicknesses of layers and regions are exaggerated for clarity, but as schematic diagrams, they should not be considered to strictly reflect the proportional relationship of geometric dimensions. The referenced figures are schematic illustrations of idealized embodiments of the present invention, and the illustrated embodiments of the present invention should not be considered limited to the particular shapes of the regions shown in the figures, but include resulting shapes (such as manufacturing-induced deviations) . All are represented by rectangles in this embodiment, and the representation in the figure is schematic, but this should not be considered as limiting the scope of the present invention.

In order to allow those skilled in the art to better understand the present invention, preferably, in the specific embodiment of the present invention, the substrate is selected from acrylic (PMMA) substrate, and the silicone rubber material used to replicate the micro-concave array is selected from polydimethylsiloxane (PDMS). ) and the ratio of its monomer and crosslinking agent is 10:1, and finally a 60cm×60cm microlens array based on UV curing material (NOA81UV glue from Norland, USA) is prepared. A method for fabricating a microlens array of the present invention will be described below through an embodiment.

Example.

As shown in FIG. 1 , the specific scheme of this embodiment includes the following steps.

(1) Design and generate the required microlens array model, and set the corresponding laser power, laser beam spot size, and laser dwell time according to the required microlens array parameters.

The schematic diagram of the microlens array model designed in this embodiment is shown in Figure 2. Each microlens model 02 is circular in shape, consistent in size, and arranged tangentially in the vertical and horizontal directions; the aperture of the microlens model 02 is 1mm, and the curved surface The radius is 18.01mm. The MC150-DLG laser dotting machine produced by Han's Yueming Laser Technology Co., Ltd. was used for laser processing, and the laser wavelength used was 10.64 μm.

First, draw the designed microlens array model using the dot design software built into the laser dotting machine, then set the laser frequency to 50KHZ, and the laser power to 100W. Adjust the laser beam spot size to be slightly smaller than the prepared microlens by adjusting the laser focus. Aperture, in this embodiment, the laser beam spot size is set to 0.8 mm; finally, the laser stay time at each point is set to 0.5 milliseconds.

(2) A clean substrate is provided and a dimple array is made on the substrate by laser dotting.

Select a PMMA substrate 01 with a flat and smooth surface, the thickness of the substrate is 3mm, place it in the aqueous solution of cleaning solution Win-10 (volume ratio is Win-10 : DI water = 3 : 97), and use an ultrasonic machine with a frequency of 32KHz to clean it for 15 minutes After spraying for 2 minutes, put it in the aqueous solution of cleaning solution Win-41 (volume ratio is Win-41 : DI water = 5 : 95), use an ultrasonic machine with a frequency of 40KHz to clean for 10 minutes, and then spray and rinse with circulating tap water for 2 minutes Finally, use an ultrasonic machine with a frequency of 28KHz to clean it in DI pure water for 10 minutes, dry it with a nitrogen gun, and then place it in a clean oven at 50°C for more than 30 minutes.

The clean PMMA substrate 01 was sent to a laser dotting machine for laser processing. After the processing was completed and cooled, it was taken out, and the remaining fines on the surface were blown away with a nitrogen gun to obtain a PMMA micro-concave array 03 as shown in Figure 3.

(3) Coating the silicone rubber prepolymer evenly on the surface of the micro-concave array, curing and separating to prepare the silicone rubber microlens array.

Take the PMMA micro-concave array 03 substrate prepared in the step (2) and seal it in a container containing trimethylchlorosilane molecules (TMCS), and take it out after about 5 minutes. At this time, the PMMA micro-concave array 03 A layer of TMCS is self-assembled on the surface of the substrate for anti-sticking. Prepare a mixture of monomer and crosslinking agent according to the required ratio of the silicone rubber, that is, configure a polydimethylsiloxane (PDMS) mixture in a ratio of 10:1 between the monomer and the crosslinking agent, and stir until uniformly mixed. Place the PMMA micro-concave array 03 substrate with a self-assembled layer of TMCS horizontally in a container, pour the polydimethylsiloxane (PDMS) mixture, and let it stand for about 30 minutes until all the bubbles are eliminated. Put it in an oven at 80°C for more than two hours, take it out after the PDMS is completely cured, separate the PDMS from the PMMA micro-concave array 03 substrate, and cut the PDMS to form the PDMS microlens array 04 as shown in Figure 4.

(4) Preparation of PDMS micro-concave arrays.

In order to transfer the PDMS microlens array 04 into a microlens array of other materials, it is necessary to prepare a PDMS micro-concave array 05 .

Take the PDMS microlens array 04 substrate prepared in the step (3), set the side of the microlens array facing up, and after treating its surface with oxygen plasma, place it in a sealed place with trimethylchlorosilane molecules ( TMCS) container, put it for about 5 minutes and take it out, at this time, the surface of the PDMS microlens array 04 substrate self-assembles a layer of TMCS for anti-sticking. Configure the polydimethylsiloxane (PDMS) mixture according to the ratio of monomer and crosslinking agent 10:1, and stir until uniformly mixed. Put the PDMS microlens array 04 substrate with one layer of TMCS self-assembled, with the side of the microlens array facing up, place it horizontally in a container, pour polydimethylsiloxane (PDMS) mixture, and let it stand for about After 30 minutes until the bubbles are completely eliminated, put the container in an oven at 80°C for more than two hours, take it out after the PDMS is completely cured, separate the PDMS micro-concave array 05 from the PDMS micro-lens array 04, and cut to form a shape as shown in Figure 5. PDMS Dimple Array 05.

(5) Transfer the silicone rubber microlens array to other materials to prepare microlens arrays of different materials;

Select a glass substrate 07 with a substrate thickness of 3mm, place it in the aqueous solution of cleaning solution Win-10 (volume ratio is Win-10 : DI water = 3 : 97), use an ultrasonic machine with a frequency of 32KHz to clean for 15 minutes, and spray for 2 minutes Finally, put it in the aqueous solution of cleaning solution Win-41 (volume ratio is Win-41 : DI water = 5 : 95), use an ultrasonic machine with a frequency of 40KHz to clean for 10 minutes, spray and rinse with circulating tap water for 2 minutes, and then reuse The ultrasonic machine with a frequency of 28KHz was cleaned in DI pure water for 10 minutes, dried with a nitrogen gun, and then placed in a clean oven at 50°C for more than 30 minutes.

Place the PDMS micro-concave array 05 in a vacuum environment for pumping, and pump out the gas in the PDMS to form a negative pressure. Then apply NOA81 evenly on the clean glass surface, and then form a negative pressure PDMS micro-concave array 05, and place the side with the micro-concave array facing NOA81, and place it horizontally on the glass surface. NOA81 is easily sucked into the PDMS dimple array 05 when dropped under negative pressure.

Expose the glass substrate with NOA81 and PDMS micro-concave array 05 to 365nm ultraviolet light for more than 2 minutes, so that NOA81 is cured, and the PDMS micro-concave array 05 is separated from it to form the NOA81 microlens as shown in Figure 6 Array 06.

(6) Subsequent polishing of the microlens array.

After the prepared NOA81 microlens array 06 is mechanically and chemically polished, a NOA81 microlens array with a smooth surface is finally formed.

The above-listed preferred embodiments have further described the purpose, technical solutions and advantages of the present invention in detail. It should be understood that the above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Within the spirit and principles of the present invention, any modifications, equivalent replacements, improvements, etc., shall be included within the protection scope of the present invention.

Claims (10)

1. A method for making a microlens array, characterized in that: comprising the following steps, S1: Design and generate the required microlens array model, and set the corresponding laser power, laser beam spot size and laser dwell time according to the parameters of the required microlens array; S2: Provide a clean substrate and make a dimple array on the substrate by laser dotting; S3: Coating the silicone rubber prepolymer evenly on the surface of the micro-concave array, preparing a silicone rubber micro-convex lens array after curing and separating, and performing polishing treatment. 2. the manufacture method of a kind of microlens array according to claim 1 is characterized in that: described silicon rubber microconvex lens array is transferred on a substrate in described step S3, prepares the microconvex lens array of this substrate . 3. the manufacture method of a kind of microlens array according to claim 2 is characterized in that: described silicon rubber microconvex lens array is transferred on a substrate, prepares the microconvex lens array of this substrate, and its specific The process is: S41: Prepare a silicone rubber micro-concave array through the silicone rubber micro-convex lens array prepared in the step S3; S42: Coating the substrate evenly on a flat substrate, placing the silicon rubber micro-concave array on the surface of the substrate, and preparing a micro-convex lens array of the substrate after curing and separation. 4. The manufacturing method of a microlens array according to claim 2 or 3, characterized in that: the material used in the base material is a transparent organic polymer material that can be cured by ultraviolet or heat, including NOA81, UV Glue, PMMA, PC, PVP. 5 . The manufacturing method of a microlens array according to claim 1 , wherein the substrate is made of organic polymer, metal, semiconductor, oxide or marble. 6. The manufacturing method of a micro-lens array according to claim 1, wherein the lens distribution of the micro-convex lens array can be adjusted arbitrarily by design software as required. 7. the manufacture method of a kind of microlens array according to claim 1, is characterized in that: the lens aperture of described microlens array and lens curvature radius are mainly determined by laser beam spot size, laser power and laser dwell time, wherein The laser beam spot size is 1 micron to 5 mm, the laser power is 1 watt to 10 kilowatts, and the laser dwell time is 5 microseconds to 5 minutes. 8. The manufacturing method of a microlens array according to claim 1, characterized in that: the wavelength of the laser used in the method is in the infrared band from 760 nm to 1 mm, and the frequency range is from 10 Hz to 10 MHz. 9 . The manufacturing method of a microlens array according to claim 1 , wherein the subsequent polishing in step S4 is mechanical polishing and chemical polishing, so as to obtain a flat and smooth lens surface. 10 . 10 . The method for manufacturing a microlens array according to claim 1 , wherein the lens size of the microlens array is 10 micrometers to 10 millimeters, and the size of the microlens array is 1 inch to 100 inches. 11 .